CJM

Its a combination of a cheap gun and too small a tank and compressor.

A friend of mine has a husky branded (home depot) compressor: http://www.homedepot.com/prel80HDUS/...rchResults.jsp

And a husky gun and it does everything fine so long as you have enough air. We plumbed in an extra 25 gallon tank he had and it helped alot!

MTL_4runner

If I was still working as a tech, you're right, I'd probably have just paid the money for a new 2135 Ti, but as a weekend warrior just doing occasional maintenance on the cars or fixing stuff around the house, I just can't justify the $150-175 people are getting even for a used one on eBay just to have it in my toolbox. If I need that much power later, I'll probably just spring for the IR2141 which puts out about 1200 ft-lbs, but that will depend if I get stuck with my 600 ft-lb gun. I haven't come across anything that stumped me yet.

MTL_4runner

If this is the compressor....


Then I see the specs are as follows:

Lubrication: Oil Free
Gauges: 2
Quick Couple: 1/4" NPT
Weight (Lbs.): 87
Shipping Weight (Lbs.): 110
Tank Size Gal.: 15 Gal
HP (Peak/Run): 4.5/1.8
Amps @115 Volts: 15
Max. PSI: 135
SCFM Air Delivery @40 PSI: 8.0
SCFM Air Delivery @90 PSI: 5.7
Pressure Release: YES
Regulator: YES

So the CFM @90 PSI is a little on the low side and a larger tank (like a 25-35 gal) might have helped make up for that a bit, the 5.7 CFM should be able to give you enough torque in short bursts to get off some pretty tough bolts with the right gun (you may need to crank up the regulator to 100 PSI). I still maintain the compressor can do it, the impact gun is the big bottleneck here.

CJM

I still say the gun, the compressor could be bigger but the gun is the biggest problem. Have you checked all the fittings to make sure the air is getting to the gun at full pressure?

linuxrunner

It's looks alot like that but it is older and a little more scfm @ 90psi i think it was 7scfm. Got it for $50 on craigslist and i had a guage i used to prove that psi and scfm were up to snuff (always ask for the recepts from craigslist sellers to ensure that things are not stolen)

I am sure it is just the gun, i will look into a bigger gun probably 500#. So if the compressor says 7scfm is that the output of the compressor/motor, or the fastest air can escape from the tank? If a compressor has high scfm do you really need a huge tank if you only take off one bolt every 10 or 15 minutes? Basicly i am asking if i need a larger tank just to use a gun for one bolt at a time? (can a big gun empty a 15 gal tank with one squeeze of the trigger)

91_4x4runner

What it's saying is that when the tank has compressed air to 90psi, it can escape at 7scfm. at 40psi, it's probably around 4scfm. A larger tank loses pressure slower than a smaller tank.

If you have a 60 gallon tank compressed to 90psi rated at 7scfm, and a 20 gallon tank compressed to 90psi rated at 7scfm, its the larger tank is obviously going to last longer without turning the pump on. It all comes down to how much noise you're willing to put up with and how much time you're willing to wait to pull off each bolt.

MTL_4runner

Very good buy on the compressor even if the tank is a bit small.

The CFM is based on the motor/compressor not the tank (although you need to be careful they aren't quoting peak CFM or DCFM, just like they often quote peak HP). The CFM measurment should be a steady state (ie sustained use) for how fast you can get air replenished into the tank and the tank itself is more like the reservoir. The two parts do work in tandem so you really couldn't just hook the airline up to the compresor only and get the same performance (since the air will be cooled and buffered in the tank), but you get the idea. The answer is for what you are doing, you should be fine. If you were using tools that need high CFM over a long period of time (sanders, grinders, etc) then you'd definately need to get a larger tank (and probably compressor too) to keep up with the sustained demand.

Here's some good articles on air compressors:
http://www.truetex.com/aircompressors.htm
http://www.jennyproductsinc.com/howtochoose.html

trailrunner55

this is what i use at work 1000#'s reverse @ 90 psi, they have the compressors at 170 psi at work tho